STANDARDChemistry-Solutions
STANDARD Chemistry Molarity and Ion Concentration MCQ Question
Type: MCQ-numerical-Medium-Class 12
How many Na⁺ ions are present in 100 mL of 0.25 M of NaCl solution?
A
0.025 × 10²³
B
1.505 × 10²²
C
15 × 10²²
D
2.5 × 10²³
Correct Answer
Option B
Detailed Explanation
The number of moles of NaCl is calculated using Molarity (M) = 0.25 mol/L and Volume (V) = 0.1 L, resulting in 0.025 mol of NaCl. Since each mole of NaCl produces one mole of Na⁺ ions, the number of Na⁺ ions is 0.025 × 6.023 × 10²³ = 1.505 × 10²².
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